Conventional open-top trailers such as chip trailers used to convey wood chips, are covered by flexible sheets such as tarps. In the prior art, a platform is typically provided at one end of the trailer so that an operator may climb up onto the platform to manually roll and unroll the tarp so as to uncover and cover, respectively, the trailer opening. In practice, however, an operator quite often is required to climb up onto the loaded trailer to assist the rolling and unrolling the tarp cover. This has resulted in accidents where, for example, in the winter time and in the dark, an operator who is expected to cover and uncover the load by himself, will slip and fall from the top of the trailer. The fall is a significant distance, often in resulting in injury.
Consequently, it is desirable, and an object of the present invention to provide, a system which relieves the practice requirement of an operator having to climb up onto, firstly, a platform elevated above the ground, and secondly, the load itself to assist rolling and unrolling the tarp cover. It is an object of the present invention to provide such a system where an operator can more safely roll and unroll the tarp cover from the ground.
In the prior art, applicant is aware of U.S. Pat. No. 5,549,347 which issued to Anderson on Aug. 27, 1996, for An All Weather Mechanically Reciprocatable Roll Tarp Cover Apparatus. Anderson teaches a mechanically reciprocatable roll top cover for covering and uncovering the open top side of receptacles such as trailers. The panel is divided into two sloping panels by a truss structure. Two primary operating drive devices are provided which include an uncovering drive device for removing the cover and a covering drive device for replacing the cover. The cover has one edge fixed at one side wall of the trailer receptacle. The opposing edge of the cover is free to travel between the opposing side walls of the trailer receptacle. The uncovering drive device includes a shaft which is rotated toward the cover's fixed edge to wind the cover onto the shaft. The covering drive device is a shaft rotatably mounted to the opposite side wall of the trailer. A plurality of flexible straps and a strap winding system are mounted to the shaft. The straps interconnect the shaft to the free edge of the cover so that when the shaft is rotated, the straps draw the cover over the truss structure. The straps are wound onto spools mounted on the shaft.
In the tarp cover unrolling system of the present invention, there is no requirement for a rotatable shaft having spools mounted thereon cooperating with straps attached to the cover so as to draw the cover across the receptacle opening. Rather, the system of the present invention incorporates a harness which is rolled up along with the tarp when the tarp is rolled. The harness is attachable to a length of line which may be pulled by the operator from the ground so as to unroll the tarp and thereby cover the trailer opening.